Question

I want to implement delete functionality using checkboxes in my struts2 application. I’m using display tag in my jsp page to show the reports. I need to provide checkboxes with reports to delete the selected reports. I have tried this code in my jsp page :

<s:form name="listPage">
<display:table name="egnreports" class="table" id="egnreports" requestURI=""  export="true" pagesize="30">

<display:column>
 <s:checkbox name="checked" fieldValue='%{egnreports.id}' />
</display:column>

<display:column value="<%=egnreports_rowNum%>" title="S.No." />

<display:column property="createDate" sortable="true" titleKey="egnreport.createDate" style="width:13.5%"/>

<-- Other Table data here -->

</display:table>
</s:form>
<c:out value="${buttons}" escapeXml="false" />

In my action class, I have used this :

 private String[] checked; 

public String[] getChecked() {

    return checked;
}

public void setChecked(String[] checked) {

    this.checked=checked;

}

When I try to retrive the selected values to delete the corresponding reports, I get a null pointer exception :

for (String code : checked) { 

    System.out.println(code + " is selected"); 
    System.out.println("id="+egnreport.getId());
        egnreportManager.remove(egnreport.getId());
        saveMessage(getText("ireport.deleted"));
        }

If I use

<display:column>
 <input type="checkbox" name="checked" value="${egnreports.id}"/>
 </display:column>

in place of s:checkbox tag, I’m able to see the values in the reports page (using firebug), but still they do not get populated in the action class.

using

<input type="checkbox" name="checked" value="${egnreports.id}"/> 

i get

<td> <input type="checkbox" value="5" name="checked"> </td> 

as rendered html, while with

<s:checkbox name="checked" fieldValue='%{egnreports.id}' />  

I get

<td> 
<div id="wwgrp_egnDeskReports_checked" class="wwgrp"> 
<div id="wwctrl_egnDeskReports_checked" class="wwctrl"> 
<input id="egnDeskReports_checked" type="checkbox" value="" name="checked"> 
<input type="hidden" value="" name="__checkbox_checked"> 
</div> 
</div> 
</td>  

Also I can’t use "${egnreports.id}" with s:checkbox to get the values of id.
Where did I go wrong? can anybody help me with this?

Answer 1

i have got the solution : i have to use fieldValue=”%{#attr.egnreports.id}” i.e,

<s:checkbox name="checked"  fieldValue="%{#attr.egnreports.id}" value="false"/>

to pass the checked values.
Also remember to include buttons inside form tag, i didn’t pay attention to this before:

<c:out value="${buttons}" escapeXml="false" />    
</s:form>

🙂